Each backlinks is considered a Vote of Confidence
Google's Voting System
Google considers every link or backlink to be similar to a vote, where some votes are more important than others. PageRank is Google’s system of counting all of the links to a page and then determining how important a page is based on its votes. These scores are then used along with many other factors to determine how well a page will rank in a search.
The initiation of the voting process transpires when a website places a link to your website on any of its pages. This is then seen by Google as placing a vote for your website. Knowing that another website possesses a link to your site or voted for you, Google consider your site significant.
Google then assesses the ranking of the website that contains your links. If that website has a PageRank of 4 to 10 backlinks are considered valuable by search engines from that site. However, having links on PageRank 0 to 3 websites often produce zero improvement through search engines.
Creating a backlink on a high-ranking and relevant website is one of the most effective ways to increase your score or PageRank. Autobacklink Service is associated with several reputable and high-ranking websites which allows us to place backlinks on sites with PageRanks of 4 and up which will have a significantly positive impact in traffic and exposure to your website.
"I found Autobacklink Service online and saw they had a promotion to get 10 free backlinks for hitting the "like button" on facebook and posting a comment on their wall. So I did, and just a few hours later I had 10 new backlinks to my website. I'm still waiting on google and yahoo to re-index the sites, I can't wait to reap the benefit of the new links for my site. You should sign up for the free links too, I know I will be buying more backlinks from Kris in the future for this and other sites. Thanks. "
"Links at the bottom of the page are treated differently than ones at the top or within the content body."
Matt Cutts on link locations